Refrigeration, an indispensable modern technology with ancient origins, continues to evolve under the pressing demand for sustainability. In India, where the domestic refrigeration market is projected to reach ₹285 billion by 2034. The growing dependence on conventional vapor compression systems poses significant environmental challenges due to their reliance on high-GWP refrigerants such as R134a (GWP = 1430). Vapor Absorption Refrigeration (VAR) systems provide a sustainable alternative because they utilize low-grade thermal energy, operate with minimal mechanical components, and can be driven by renewable energy sources. This study presents a comprehensive experimental and comparative evaluation of solar-driven VAR systems integrating two renewable energy conversion pathways-a solar thermal flat plate collector (FPC) and a solar photovoltaic (PV) system. A 100 LPD solar flat plate collector was thermally coupled with a VAR generator through a copper heat exchanger optimized for insulation and mass flow, while a 100 W polycrystalline solar PV module with a 12 V/8 A charge controller and 12/40 Ah battery was employed to electrically drive the same system. The FPC-integrated VAR system achieved an evaporator temperature of 12 °C, and an average thermal efficiency of 35.3%, corresponding to a coefficient of performance (COP) of 0.14. Conversely, the PV-integrated VAR system attained a minimum evaporator temperature of 9 °C, maintaining a stable operational efficiency of approximately 9% and a COP of 0.12.
Selvaraj et al. (Tue,) studied this question.